Permittivity measurement of construction materials in free space: model based high precision measurement of the standing wave distribution

摘要

Standing wave method is easily used for permittivity measurement of construction materials in free space. We have improved the accuracy of the method by developing a model of the measurement system. We assumed that the standing wave is generated by the incident wave, reflected wave and scattered waves from the assumed scattering wave source on the material edge. Through model fitting by the least squares method, we can estimate the electric characteristics of the material accurately from the reflection coefficient.